There is a need to provide a lathe having multiple adaptability for various uses but in particular for use in wood turning although the lathe of the present invention may be used in respect of other operations with respect to other materials such as metals and composite materials.
Lathes and cutting machines are known for turning rotationally symmetrical elements such as wooden spindles or balustrades. Generally a work piece is mounted in chucks and is spun and a knife or set of knives are urged towards the work piece causing wood outside the desired profile to be chipped away.
Wood lathes are known, and most lathes are cast having a fixed bed, a headstock and a tailstock. There have been known lathes hat beds which can be raised or lowered, and moved towards or away from a headstock along a centreline axis between a headstock and a tailstock. Indeed it has been known for a lathe to include a rotatable headstock and even beds capable of translatory movement.
Despite advances in the art of the type mentioned there remain practical disadvantages. For example, prior art lathes do not enable an operator to effectively and safely gain access to all surfaces of an article to be worked on. One attempt to address this problem has involved manually transferring an article to be worked on to a reverse side of a headstock. While this may allow an operator working access to a backside of an article to be worked on, further practical problems arise because in the reverse position an operator will be required to work left handed as a spindle is effectively rotating in an opposite direction. Further attempts to overcome this problem have involved a rotatable headstock, however this type of arrangement still requires an operator to substantially change position and can adversely interfere with vacuum hoses and attachments connected thereto.
Further disadvantages of the prior art lathes include an inability to enable efficient turning of a large blank. In particular if a headstock is able to be rotated to accommodate a large blank, the tailstock cannot be properly brought into an alignment position. In this situation the blank is not properly supported not is it safely balanced. As a result significant vibrations will occur in prior act lathes which are hazardous for lathe operators.
In U.S. Pat. No. 491,236 there is disclosed translatory movement of a bed section, however translatory movement precludes any use of a tailstock to help support heavy or bulky work which must therefore be carried on spindle bearing alone.
It is generally a desirable characteristic of prior art lathes to provide a means of attaching an article to be worked on to a faceplate so as to minimise or prevent marks on articles created by conventional fastening means. Prior art lathes have at least in part addressed this desire by means of applying vacuum although occupational health and safety issues associated therewith still require improvement.
In U.S. Pat. No. 2,852,264 there is disclosed a vacuum chuck which enables a vacuum source to be connected to a faceplate via a swivel connection mated with a spindle bore of a lathe by a tapered plug. This type of arrangement is potentially very dangerous since if there is even any slight imbalance or misalignment the vacuum tubing connected to the lathe spindle can be dislodged. At relatively high rates of spindle rotation any dislodgement of vacuum tubing at such high rates may well be fatal to an operator.
U.S. Pat. No. 5,445,052 provides a vacuum chuck for a lathe. In particular this vacuum chuck incorporates a rotary vacuum coupling connected to a vacuum pump which is attached to an outer end of a vacuum tube located centrally within a spindle bore. In many instances this type of attachment is extremely unsafe because it relies on an external rotating extension of a spindle to permit use of a commercially available rotary union to provide the means of inducing vacuum through the spindle to a chuck.
Finishing and polishing operations usually carried out on a vacuum plate type chuck are made at relatively high spindle RPM (800-2000 RPM) and at such speeds a hose can cause severe injury or death if this rotary union seizes up causing the hose to break off and rotate in a whip like manner.
This type of accident is known to have occurred add The Nichols Jnr. invention does not show otherwise.
The Omega vacuum invention provides for a safe internally enclosed method of inducing a vacuum or partial vacuum through the lathe spindle without additional moving parts, and can operate at speeds of 3000 RPM or more without, damage or safety problems.
The present invention seeks to ameliorate one or more of the problems of the prior art.
The present invention seeks to overcome those problems by providing a universal lathe machine which will substantially enable an operator to gain working access to all surfaces of an object without having to manually move the object, as well as enabling turning of large blanks while a machine remains safely in balance.
A further object of the invention is to provide a modified vacuum induction system which substantially improves occupational health and safety standards over the prior art lathe machines.